Dump truck body tilting mechanism



May 25, 1954 J. WASINGER DUMP TRUCK BODY TILTING MECHANISM 2 SheetsSheet 1 Filed March 20, 1950 Z II.

Fig. I

I5 Eli/14 Fig. 3

INVENTOR. LE ONARD J. WASINGER ATTORNEYS May 25, 1954 J-. WASINGER DUMP TRUCK BODY TILTING MECHANISM 2 Sheets-Sheet 2 Filed March 20, 1950 Fig. 7

INVENTOR. WASINGER W 2 mm LEONARD J.

Fig. 8

ATTORNEYS Patented 25, 1954 2,679,433 DUMP TRUCK BODY TILTING MECHANISM Leonard J. Wasinger, Wakeeney; Kans., assignor to Trego Manufacturing-Company, Inc., Wa-

keeney,

Kans., a corporation of Kansas Application March'20, 1950, SerialNo.*1'50,637

4 Claims.

tured and installed without tools.

urther object is to produce a cable operated A f mechanism of the type employinga winch drum,

having a force multiplying the cable between the winch be operated.

The above and any other objects that may apdevice positioned in drum and object to pear as the description proceeds are attained'by means of a construction and an arrangement of parts that will now be described in detail, for which purpose reference will be had to the acelevation body in elevated position, with parts broken away to better disclose the construction;

Figure 2 is a section taken on line 22 of Figure 1;

Figure 3 is a top taken on line 3-3, Figure 1, the being indicated by broken lines;

Figure 4 is a side elevation showing the parts in normal down position, portions being broken away to better disclose the construction;

Figure 5 is a side elevation, similar to that shown in Figure 1, and shows a slightly modified construction, with the dump body in raised position;

Figure 6 is a section taken on line 6-4-3, ure 5;

Figure 7 is a top plan view, taken on line 1-7, Figure 5;

Figure 8 is a side elevation, with parts broken away to better disclose the construction;

down position Figpartly' in section,

plan View, partly in section,v

Figure :9 is 5a"diagrammatic view showing two positions. :of theiembodiment illustrated in Figures 1otoL4; and:

Figure :10. is a'view similar to that of Figure 9 showing:twosimilarpositions of the parts shown in"Figures 5 to 8.

Referring now to the meral I 0 shown). Anengine'is carried by the front end of the convenience, been shown serving as a pivot about The dump body has been indicated in atgeneral way and, .as

are attached. The elevating or dumping mechanism comprises, in addition to the winch, a shaft #9 whose 36 by a link 25 is a pulley block having two pulleys 25 that rotate about pivot 27. Links 28 have their rear ends conwith arms 2| and 24130 form Onevendeof cablea34 isattachedrto pivot 32 byte,

a stress: triangle;

at the time lifting arms were in U-bar 35 and passes rearwardly, thence downwardly over one of pulleys 26, thence forwardly and up over pulley 3|, thence rearwardly and downwardly over the other pulley 26, thence forwardly to winch drum l3.

Let us now assume that the parts are in the position shown in Figure 4 and that the winch drum is operated to wind the cable thereonto. When the tension in the cable is P the force tending to move pivots 21 and 32 toward each other is equal to 3P. It will be observed that, due to 26 and SI must move in opposite this therefore prosume that pulleys 26 rotate on a fixed pivot, that is, with links 28 omitted, then the force acting to turn shaft is would be 3P. With the arrangement shown pivots 2i and 32 approach each other at the same rate, that is, when pivot 32 moves one foot pivot 21 will also move one foot in the opposite direction, and this requires six feet of cable to be wound onto the winch drum. It is evident, therefore, that by the use of links 28 producing an equal and opposite movement of the pivots and pulleys, the rotary force or torque exerted on shaft i9 will be doubled. If we examine Figure 4 carefully it will be observed that the rate at which pivot 21 moves longitudinally varies with its angular position, first increasing to a maximum when it is perpendicular and decreasing from 90 to 180 degrees. The torque exerted on shaft l9 per unit pull in the cables will therefore be a maximum when the lever arm equals the distance from center of shaft It to pivot 32.

It is evident that when the parts are m sition shown in Figure 4 the lifting by rollers 23 per unit torque will be a minimum and that it increases as the dump body rises, approaching a maximum when the parts reach the position shown in Figures 1 and 2. If lines 21-46 and iii-32 were vertical, as shown in Figure 9, the position shown in Figure 4 the torque exerted on shaft l9 per unit cable tension would be a maximum at the time when the lifting force of arms 2| per unit torque was a minimum and that the torque per unit cable tension would decrease as the lifting force of arms 21 increased. Owing to structural considerations the parts are usually so arranged that the torque per unit tension increases to a maximum and then decreases.

In Figures 5 to 8 somewhat similar results are obtained by a slightly different mechanism which will now be described. The trucx frame comprises two parallel channel bars lilct. Near the front of the frame where engine E is located a winch shaft ii is mounted for rotation in bearings l2 and carries a winch drum !3. Brackets M are attached to the frame members Eta near their rear ends and serve as supports for shaft 16 on which bearing blocks it, that serve as supports for the dump body i! whose frame comprises two channels i8, is supported.

Shaft 19a has its ends supported by brackets Ella, and is made in two parts, each of which terminates in a cross bar 3': whose ends are joined by pivots 33 on each of which a pulley 39 is mounted. Lifting arms Zia have their ends welded to shaft Na and their outer ends are connected by a bar or shaft llii on the ends of which rollers ii are journaled, which travel in the channels of frame members l8 as shown more particularly in Figure 6. Braces 4? connect the outer ends of the lifting arms with cross bars 31.

1 tilting the A pulley block 43 is connected with shaft l6 or some other stationary anchor. Cable 34 has one end anchored to drum l3 and the other connected with bar 43 and passes about pulley 43, thence over the upper pulley 39, thence under the lower pulley 39.

Let us now assume that the parts are in the position shown in Figure 8, in which position the tension in that part of cable 34 that extends from pulley A3 to shaft 40 exerts practically no torque tending to rotate shaft 19a and the lifting arms. In this position the tension in the cable tends to turn shaft iiia. counterclockwise, the lever arms being the perpendicular distances from the center of shaft 59a to the cables. As the shaft rotates the torque increases, due to the increased lever arms, and at the same time the force exerted by the cable on the ends of the lifting arms is increasingly converted into torque. If cross arms were displaced at an angle of about 90 degrees from the lifting arms as shown in Figure 10 the torque due to the coaction between the cable and pulleys 39 would be a maximum when the torque due to the force exerted by the cable on the lifting arms is a minimum and as the shaft turns the former will decrease while the latter increases. For structural reasons the angular relation of the parts has been selected as shown.

From the above it will be apparent that the body dumping mechanism has been so constructed that the torque applied to the lifting arm shaft is near maximum when the lifting arms are in their least effective position and in which the torque, after reaching its maximum per unit cable tension, decreases while the effectiveness of the lifting arms increases.

Having described the invention, new is:

1. In a power operated dump truck of the type having a wheel supported frame, spaced side members, an engine supported by the frame adjacent its front end, an engine operated winch drum, and a dump body pivoted to the rear end of the frame for tilting movement; means for dump body by power from the engine comprising, a transversely extending shaft positioned between the frame members and mounted for pivotation, said shaft having a lifting arm non-rotatably attached to it at each end, positioned to slideably engage the under side of the lifting body, two crank arms non-rotatably attached to the shaft, one adjacent of, said arms extending at an angle to the lifting arms, a pulley block connected with the frame near the rear end thereof, another pulley connected with the ends of the crank arms by means of links, a cable having one end connected with the winch drum and the other connected with the shaft at a point spaced from the center thereof, the cable passing from the point of connection with the shaft rearwardly about the pulley connected with the frame, thence forwardly about the pulley connected with the shaft, thence rearwardly about a second pulley on the pulley block, and thence forwardly to the winch drum.

2. In a dump truck of the type having a wheel mounted frame having two spaced frame members, an engine at the front end thereof, a power operated winch adjacent the engine, and a dump body supported on the frame and mounted for pivotation about an axis transverse of the frame; means operated by power from the engine for tilting the dump body, comprising a pivoted torque shaft extending across the frame, with its ends pivoted on the frame members, two lifting what I claim as turning the shaft and lifting arms in a direction to raise the front ends of the arms, said means comprising a pulley attached to the rear end of for rotation about a pivot radially spaced from 10 the frame, crank arms rigidly attached to the shaft, a pulley operatively attached to the ends of the crank arms and positioned above the shaft, a cable encircling the pulleys, one end of the cable being attached to a pulley mounting, the other connection, a crank arm non-rotatably connected 15 end being attached to the winch drum whereby block and the axis of the pulley on the torque 20 thereby turning the shaft in a direction to raise the ends of the lifting arms.

4. A device in accordance with claim 3 in which the force multiplying device comprises two pulleys positioned on opposite sides of the shaft, the cable passing over said pulleys, the bights of the cable facing a diametrical plane, the angles of the torque h ft, h cable p s i r rwardly from 25 bights being minimum when the dump body is block, thence forwardly to its connection with 0 horizontal.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Lally Feb. 20, 1912 I-Iough Feb. 12, 1924 Graham Nov. 9, 1926 Smith May 24, 1949 Findley Sept. 20, 1949 Jacobs et al Jan. 10, 1950 Frenzel Apr. 24, 1951 

